According to sleep medicine recommendations, the orthopedically/anatomically correct positioning of the body during sleep is a critical factor for achieving healthy sleep. It is well known in the fields of sleep medicine and orthopedics that, in addition to the lumbar vertebral region, the shoulder zone in particular must be properly relieved of pressure and correctly stabilized during sleep.
The shoulder joint forms the movable connection between the shoulder blade and the humerus. Of all the ball-and-socket joints in the human body, the healthy shoulder joint has the greatest mobility, since it is secured primarily by the rotator cuff. Thus mobility is essentially unrestricted by the body framework. Moreover, the position of the entire shoulder joint can be changed by moving the shoulder blade. This allows the arm and the hand to be moved to many different positions, and to perform a very wide range of activities.
Statistics show that in Germany alone, 10-15% of adults suffer from chronic shoulder pain. Frequently this pain is caused by inflammatory disorders (omarthritis). Considerable pain and functional restriction can also be caused by impairment resulting from accident or degeneration. Another frequent complaint is irritation of the mucous membrane in the shoulder joint (Bursitis subacomealis). The orthopedic/anatomical lowering of the shoulder zone is of paramount importance for both regeneration of the shoulder zone and overall sleep quality.
In terms of mattress foundations, in orthopedic/anatomical terms, double-sided, preferably freely suspended slatted bed frames combined with a natural rubber mattress measuring 5.0-7.5 cm in thickness, and a virgin sheep's wool pad of proper weight for the climate where the bed is located have proven particularly advantageous.
A double-sided lamellar slatted bed frame is disclosed, for example, in EP 0 385 121 A1. The lying surface has an upper and a lower row of slats, arranged parallel to one another and connected to one another by elastic elements extending transversely to the slats, wherein the elastic elements have tabs on the top and bottom, into which slats can be inserted. The disadvantage of this known lying surface with two slat planes is that the heavy strain exerted by a heavyweight person sleeping on said surface results in an unfavorable distribution of pressure in the lying surface. Moreover, the slatted bed frame is not suitable for persons with shoulder disorders, since the pad surface is designed as having an even degree of hardness.
With double-sided slatted bed frames, it has likewise proven disadvantageous that the weight of the body in the shoulder region often results in excess counterpressure in the lower row of slats, which can lead to tension and circulation problems during sleep.
Studies and surveys have shown that approximately 60% of all people are side sleepers. This is the most popular sleeping position because it relieves pressure on the organs, the spine and the joints. Side sleepers who have broad, highly developed shoulders in particular need a flexible, automatically adjustable device for lowering the shoulder zone in order to relieve pressure on the cervical vertebrae and allow the shoulder region to sink into the mattress in accordance with orthopedic/anatomical requirements.
A number of structural mechanical and material-based shoulder zone lowering devices for double-sided slatted bed frames exist, which are designed for positioning the shoulder region properly in orthopedic terms. However, the shoulder zone adjustments offered by these devices do not function adequately from a sleep medicine and orthopedic standpoint. Such functional shoulder zones are particularly important for people whose shoulder joints are sensitive to pressure but who sleep primarily on their sides. This is the only way to prevent pain pulses that may disturb sleep, while at the same time promoting regeneration of the shoulder zone through the sleep process. In particular, people who suffer from acute or chronic shoulder problems such as calcific tendonitis of the shoulder, shoulder arthritis, impingement syndrome, tears in the rotator cuff, etc., or who suffer from sensitivity to pain following an accident and/or surgery are affected by this.
One prior solution involved removing approximately 5-6 slats from the upper row of slats in the shoulder region. The resulting opening, combined with the mattress and the mattress pad, enabled better yielding in the shoulder zone. At the same time however, during the sleep phase in which muscle tone decreases substantially the necessary stabilization and support of the highly mobile shoulder joint is lacking.
It is also possible to remove 5-6 slats in the shoulder region from the lower row of slats, closer to the floor. Although this reduces upward pressure in the region above the gap in the slats, it in turn leads to a decrease in the bearing pressure in the region of the shoulder. Thus one of the disadvantages is that, although the bearing pressure is reduced, the shoulder is not able to sink far enough downward. This disadvantage is perceptible particularly with more significant movements of the body, and can undesirably cause the sleeper to awaken if his shoulders are sensitive to pressure and pain.
Another known method consists in providing the slats of the shoulder region of the upper row of slats with thinner slats that have been cut with grooves or holes. This results in a decrease in the tensile force of the individual slats—and a reduction in bearing pressure. The disadvantage is that an effective adjustment to different body sizes, body types and especially different body weights is very expensive.
DE 103 43 638 B4 discloses a slatted bed frame which has a plurality of upper slats arranged transversely or perpendicular to a longitudinal axis of the frame, with each slat being held at both ends on a slat support or on a slat support section and forming a slatted bed frame/pad surface for a mattress pad. In the shoulder region, the slatted bed frame has a recess, in which an elastic element is arranged, which forms part of the slatted bed frame/pad surface and which is supported on the lower slat support or on the lower slats.
The elastic element can therefore be easily inserted into the resulting opening or recess and rests on the lower row of slats. A certain material-based softness factor can thereby be achieved. The disadvantage of this type of bearing is that it is often insufficient from an orthopedic standpoint, since such padded inserts react only passively to body movements and to the respective bearing pressure. As a result, the actual shoulder zone lowering device combined with the mattress resting thereon is inadequate in most cases, since a sturdier padding material will not allow the shoulder to sink far enough downward, and a softer padding material will produce an insufficient stabilizing and supporting effect.
One significant disadvantage of the embodiment according to DE 103 43 638 B4 is that no, or an insufficient, interactive connection between the elastic element and the slatted bed frame is provided. The elastic element is merely loosely placed in the opening produced by the removed slats, and rests flat on the lower row of slats. In addition, double-sided slatted bed frames physically exert a counterpressure upward due to the lower row of slats. This occurs particularly in the region of the lower back and in the shoulder region, where the bearing pressure is particularly high.
Placing the elastic element on the lower row of slats forces the elastic element upward toward the upper slats, which often prevents adequate yielding to the shoulder. Thus two hard transitions are produced—one between the elastic element and the slatted head section and one between the elastic element and the remaining, slatted lower part of the frame.